It really depends so much on the email. It is easy enough to have your first name feed into a form email so it looks personal but is definitely not. So "Hi, Flash! I have some great tiddly winks shops near you . . ." is likely to be a form letter, especially if I have never requested or performed a tiddly winks shop and 'near you' is over 500 miles away. No response expected or appreciated other than 'sure, sign me up'. Then there is "Hi Flash! The tiddly winks shops you did for me last quarter you are back in rotation for and I can give you up to the 4 of them if that works for you. They are at _________, ___________, __________ and _______________ and I may still have ____________ available if you are interested." This email represents part of an ongoing conversation and I will respond with requests for the one(s) I want or a 'thanks for thinking of me but I can't this round because my schedule is a mess' etc.